ORIGINAL RESEARCH article
Front. Astron. Space Sci.
Sec. Space Physics
This article is part of the Research TopicHeliophysics Big Year: Education and Public Outreach ReportsView all 18 articles
Characterizing Ionospheric Variability through HF Doppler Measurements: A Statistical and Numerical Ray Tracing Analysis
Provisionally accepted
Sabastian Carlos Fernandes1*
Gareth Perry1
Tiago Trigo1
Nathaniel Anthony Frissell2John Gibbons3Kristina Collins4- 1Center for Solar-Terrestrial Research, New Jersey Institute of Technology Jordan Hu College of Science and Liberal Arts, Newark, United States
- 2Department of Physics and Electrical Engineering, University of Scranton, Scranton, United States
- 3Sears Undergraduate Design Lab, Department of Electrical, Computer and Systems Engineering, Case Western Reserve University, Cleveland, United States
- 4Space Science Institute, Boulder, United States
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High-frequency (HF) skywave propagation relies on the ionosphere, making it susceptible to ionospheric variability. This study analyzes long-term Doppler residual measurements of a 10 MHz HF link between Fort Collins, CO, and Newark, NJ, to characterize the impact of ionospheric conditions on the link. We report that daytime measurements of Doppler variability exhibit Cauchy statistics, while nighttime measurements show a combination of exponential and log-normal statistics. These patterns correlate with solar activity and solar zenith angle. We also use PHaRLAP numerical ray tracing simulations through the IRI 2020 ionosphere to provide insights into signal ray paths and the altitudes of the ionosphere contributing to the observed Doppler shifts. By examining diurnal variations and statistical properties of Doppler residuals, this study aims to enhance our understanding of ionospheric dynamics and their influence on HF signal characteristics.
Keywords: Amateur radio, doppler, high frequency, Ionosphere, propagation, Ray tracing, Skywave, variability
Received: 26 Sep 2025; Accepted: 10 Feb 2026.
Copyright: © 2026 Fernandes, Perry, Trigo, Frissell, Gibbons and Collins. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Sabastian Carlos Fernandes
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